With a density functional theory method, we studied computationally the size dependence of adsorption properties of metal nanoparticles for CO as a probe on Pd(n) clusters with n = 13-116 atoms. For large particles, the values slowly decrease with cluster size from the asymptotic value for an (ideal) infinite surface. For clusters of 13-25 atoms, starting well above the asymptotic value, the ad...

We present the first results of a detailed abundance analysis, based on VLT observations, of giant stars in the very metal-rich globular cluster NGC 6528. We will, we hope, be able to tie the horizontal branch abundances (see e.g. Carretta et al. 2001) to those of the more luminous giants (see CMDs). For the very similar cluster NGC 6553 studies of different types of stars have yielded very dis...

Electronic spectra are reported for the metal cluster (Tef) and metal cluster complex (Ag+-benzene, Mg'-C02) cations. These ions are generated by laser vaporization in a pulsed nozzle source, jet-cooled, mass-selected with a reflectron time-of-flight spectrometer, and dissociated on resonance with a tunable dye laser. Electronic excitation spectra are recorded by monitoring the appearance of th...

We discuss the existence of a mass-metallicity relation among galactic halo globular clusters. The lack of any luminosity-metallicity correlation in globular cluster systems has been used as an argument against self-enrichment models of cluster formation. We show that such a relation is statistically present among the galactic Old Halo globulars. This observational correlation implies that the ...

The size dependence of the electronic structure of Pd clusters deposited on an ordered Al203 film on Re(0001 ) has been studied using angle-resolved photoemission in conjunction with synchrotron radiation. The appearance of dispersion effects along directions both parallel and perpendicular to the substrate surface with increasing cluster size is observed, which is attributed to the formation o...

We report a numerical investigation on the catalytic growth mechanism of a single-walled carbon nanotube (SWNT) inside a template SWNT, that is, formation of a double-walled carbon nanotube (DWNT). The molecular dynamics simulations together with complementary ab inito calculations suggest that the DWNT formation from thermally annealed metallocene-encapsulating SWNT goes through formation of m...

Light emission during the collision of ions and cluster ions on a metal surface covered by rare gas matrices of variable thickness is reported. The light intensity as a function of distance from the metal surface follows the classical image dipole theory. The spectral signature of the light corresponds to the fluorescence of the neutral cluster species deposited as well as to fragments. The nat...

1 Introduction Diffusion-controlled growth of metal nanostructures and thin films on metallic and insulating substrates is important from both theoretical and practical points of view, including many technological applications, such as catalysis and microelectronics. Theory is challenged to describe two modes of thin film growth: monolayer-by-monolayer regime or 3D metal cluster formation [1]. ...

A combined study utilizing anion photoelectron spectroscopy and density functional theory was conducted to search for four-atom, chiral, metal, and mostly metal clusters. The clusters considered were AuCoMnBi(-/0), AlAuMnO(-/0), AgMnOAl(-/0), and AuAlPtAg(-/0), where the superscripts, (-/0), refer to anionic and neutral cluster species, respectively. Based on the agreement of experimentally and...

Nitrogenase, [FeFe]-hydrogenase, and [Fe]-hydrogenase enzymes perform catalysis at metal cofactors with biologically unusual non-protein ligands. The FeMo cofactor of nitrogenase has a MoFe7S9 cluster with a central carbon, whereas the H-cluster of [FeFe]-hydrogenase contains a 2Fe subcluster coordinated by cyanide and CO ligands as well as dithiomethylamine; the [Fe]-hydrogenase cofactor has C...